Modeling the high-temperature creep behaviors of 7075 and 2124 aluminum alloys by continuum damage mechanics model

The high-temperature creep behaviors of 7075 and 2124 aluminum alloys are studied by the constant-stress uniaxial tensile creep experiments. Constitutive models for describing the high-temperature creep behaviors of the studied aluminum alloys are established based on the continuum damage mechanics (CDM). Firstly, the continuum damage mechanics (CDM) models are simplified to describe the primary and secondary creep of 7075 aluminum alloy. Secondly, because the effects of the applied stress on the creep damage during tertiary stage are not completely considered in the original CDM model, the modified constitutive models are proposed to predict the creep-rupture behavior of 2124 aluminum alloy. A stress exponent D, which can preferably reveal the effects of the applied stress on the creep damage, is introduced into the modified model. The results show that a good agreement between the measured and predicted results is obtained, which confirms that the established creep constitutive models can give an accurate and precise estimate of the high-temperature creep behaviors for 7075 and 2124 aluminum alloys.

► The high-temperature creep behaviors of 7075 and 2124 Al alloys were investigated. ► A stress exponent is proposed to preferably reveal effects of the stress on creep damage. ► The established CDM models correlate well with the experimental results.